WO2012029860A1 - Optical fiber cleaving tool - Google Patents

Abstract

The present invention pertains to an optical fiber cleaving tool for cleaving optical fibers at an angle such that a given inclination is maintained relative to the axial direction, and forms a high-quality cleaved surface with a high degree of precision. The tool is provided with a pair of anvils (20A, 20B) for pressing and bending the optical fiber (2) inserted therebetween into an S-shape, and a pair of clamps (40A, 40B) for pulling the optical fiber (2), and the optical fiber (2) is cut with a blade (53) while being subjected to tensile stress and bending stress independently.

Description

Optical fiber cutting tool

The present invention relates to an optical fiber cutting tool for cutting an optical fiber so as to have an angle with a certain inclination with respect to the axial direction (cleave).

In recent years, high-speed broadband networks are spreading rapidly around the world, and they are widely used in ordinary households. For this reason, it is necessary to assemble the optical fiber connector in a general house. When assembling an optical fiber connector in a general house, the required length of the optical fiber differs depending on the house, and the optical fiber connector is cut by cutting the optical fiber to an appropriate length in the field according to the house. It needs to be assembled. For this purpose, a hand tool type optical fiber cutting tool that can be used in the field is required.

Here, when assembling the optical fiber connector, the optical fiber is cut so as to form a high-quality and high-precision cut surface that is typically inclined by 8 ° with respect to the plane perpendicular to the axis of the optical fiber. There is a need.

Patent Document 1 discloses an optical fiber cutting method in which bending stress is generated in a portion between two supports of an optical fiber, and the optical fiber is cut (cleaved) between the two supports with a blade in that state. It is disclosed. Bending stress is generated by holding an optical fiber between two spaced apart supports and displacing one optical fiber relative to the other support.

However, although the optical fiber cutting method disclosed in Patent Document 1 generates bending stress in the optical fiber due to the displacement of the support, it prevents tensile stress from being generated in the optical fiber. For this reason, there is a possibility that the optical fiber cannot be cut at a stable angle, and a cut surface that is greatly curved, so-called roll-off may occur. When a large roll-off occurs, a high insertion loss occurs (see Non-Patent Document 1). Although the size of the defect on the cut surface of the optical fiber needs to be 20 μm or less (see Non-Patent Document 2), if the method of Patent Document 1 is adopted, the occurrence of roll-off greatly exceeding this standard is expected. .

In Patent Document 2, an optical fiber is clamped between a spring having two clamping legs and a rotatable clamp block, and an S-shape is formed on the optical fiber by an anvil corner and a corner of one clamp block. An optical fiber cutting tool is disclosed that forms a curved curve and cuts the optical fiber with a blade edge between the corners.

In the case of the optical fiber cutting tool disclosed in Patent Document 2, both the bending stress and the tensile stress can be applied to the optical fiber, and a cut surface with reduced defects may be formed. However, in the case of the optical fiber cutting tool disclosed in Patent Document 2, both the bending stress and the tensile stress that are applied to the optical fiber in one operation are adjusted to optimum values. It is difficult to do. In addition, since the frictional force is used to generate the tensile stress, it is difficult to always apply a stable tensile stress. Furthermore, it is expected that bending stress and tensile stress acting on the optical fiber vary greatly from one optical fiber cutting tool to another.

Japanese Patent Laid-Open No. 5-203813 JP-T-2002-515141

TIA STANDARD FOTP-179 “Inspection of Cleaved Fiber End Faces by Interferometry”, TIA-455-179 May 1988 (reaffiliated March 2007) TELECOMMONS Telcordia Technologies “Generic Requirements for Optical Fiber Clevers”, Telcordia Technologies Generic Requirement, GR-264-COR

In view of the above circumstances, an object of the present invention is to provide an optical fiber cutting tool capable of forming a high-quality, high-accuracy cut surface.

The optical fiber cutting tool of the present invention is
The optical fibers are separated from each other in the insertion direction in which the optical fiber is inserted, and are also separated from each other in the pushing direction intersecting the insertion direction, and the optical fibers inserted during the separation are advanced in the pushing direction and opposite to each other. A pair of anvils to push and bend;
The optical fiber inserted between the pair of anvils grips the portions before and after the insertion between the pair of anvils, and one moves relatively in a direction away from the other to apply tension to the optical fiber. A pair of clamps;
A blade that cuts the optical fiber by being pressed against a portion sandwiched between the pair of anvils of the optical fiber that is pushed and bent by the pair of anvils and is held and pulled by the pair of clamps. It is characterized by that.

The optical fiber cutting tool of the present invention includes a pair of anvils and a pair of clamps, and applies bending stress to the optical fibers with the pair of anvils and applies tensile stress with the pair of clamps. For this reason, the bending stress and the tensile stress can be adjusted independently of each other, and a high-quality and high-accuracy cut surface can be formed on the optical fiber.

Here, the optical fiber cutting tool of the present invention,
With a base,
The pair of anvils are integrally installed on the base as a rotation block limited to rotation within a predetermined rotation angle,
The pair of clamps are installed on both sides of the insertion direction on the base, with the rotation block in between,
A pair of anvils are separated from each other in the insertion direction, and the optical blocks inserted between the pair of anvils are separated from each other in the pushing direction in a state where the rotation block is rotated in the first direction. It is preferable that the pushing direction bends in the opposite direction to each other by rotation in the direction opposite to the first direction.

When the optical fiber cutting tool is configured in this way, the optical fiber can be cut easily so that a high-quality, high-accuracy cut surface is formed on site.

Further, in the optical fiber cutting tool of the present invention, the tensile stress σ _t and the bending stress σ _b of the optical fiber,

However,
σ _t : Tensile stress σ _b : Bending stress L: Distance in the insertion direction between the pair of anvils L1: Distance in the insertion direction from the first anvil to the blade of the pair of anvils L2: Pushing direction between the pair of anvils Distance T: Optical fiber tension E: Young's modulus of optical fiber I: Second-order moment of optical fiber r _f : The combination of tensile stress σ _t and bending stress σ _b expressed by optical fiber radius
(Σ _t , σ _b ) = (0.08 GPa, 0.5 GPa), (0.2 GPa, 0.5 GPa), (0.2 GPa, 0.6 GPa), (0.16 GPa, 0.9 GPa), (0 .12 GPa, 1.3 GPa), and (0.08 GPa, 1.4 GPa), the distances L, L 1, and L 2 are set so as to be within the region surrounded by the points, and the pair of clamps has a tension T It is preferable that it is what gives.

If the optical fiber cutting tool is adjusted in this way, it is possible to avoid the occurrence of defects due to the optical fiber cutting.

As described above, according to the optical fiber cutting tool of the present invention, it is possible to easily cut an optical fiber by forming a high-quality, high-accuracy cut surface.

It is a top view of the optical fiber cutting tool as one embodiment of the present invention. It is the figure which showed the 1st procedure of the optical fiber cutting | disconnection, and the motion of each part of the optical fiber cutting tool accompanying it. It is the figure which showed the 2nd procedure of the optical fiber cutting | disconnection, and the motion of each part of the optical fiber cutting tool accompanying it. It is the figure which showed the 3rd procedure of the optical fiber cutting, and the motion of each part of the optical fiber cutting tool accompanying it. It is the figure which showed the operation | movement of each part of the 4th procedure of an optical fiber cutting, and the optical fiber cutting tool accompanying it. It is the figure which showed the 5th procedure of the optical fiber cutting, and the motion of each part of the optical fiber cutting tool accompanying it. It is the figure which showed the 6th procedure of the optical fiber cutting | disconnection, and the motion of each part of the optical fiber cutting tool accompanying it. It is a schematic diagram of the part pinched | interposed into two anvils of an optical fiber. It is the figure which showed the optimal range of tensile stress and bending stress.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a plan view of an optical fiber cutting tool as one embodiment of the present invention.

The optical fiber cutting tool 1 has a plate-like base 10 on which necessary components are mounted. The optical fiber cutting tool 1 can be easily carried, is brought into an optical fiber wiring site such as a general house, and used on a desk or floor. Alternatively, the optical fiber cutting tool 1 may be used while being held in a hand as a hand tool.

A rotating block 20 is mounted almost at the center of the base 10. The rotating block 20 has a first anvil 20A and a second anvil 20B, and the first and second anvils 20A and 20B are connected to each other by a connecting portion 21 and integrated. As shown in FIG. 1, the rotary block 20 has an opening 22 that opens in a fan shape when seen in a plan view, and a hole 21 a is formed in the connection portion 21.

The rotating block 20 is mounted on the base 10 so as to be freely rotatable. However, two pins 11 and 12 are erected on the base 10, and the rotation block 20 is limited to rotation within a predetermined rotation angle by these pins 11 and 12. That is, the pin 11 enters the hole 21 a formed in the connection portion 21 of the rotary block 20. The rotation in the first direction indicated by the arrow A in FIG. 1 is restricted so that the pin 11 does not rotate any more by contacting the edge of the hole 21a. Further, the rotation in the direction opposite to the first direction indicated by the arrow A direction is limited so that the first anvil 20 </ b> A abuts against the other pin 12 so as not to rotate further as shown in FIG. 5 described later. Has been.

Further, on the base 10, a rotation operation unit 30 for rotating the rotation block 20 is provided. The rotation operation unit 30 includes two rails 31a and 31b provided on the base 10 and extending parallel to the x direction, and an operation block 32 supported by the two rails 31a and 31b so as to be freely movable. And an arm 33 extending from the operation block 32 toward the rotary block 20. A crank 33 a is provided at the tip of the arm 33. The crank 33a is engaged with the rotating block 20 so as to rotate the rotating block 20 in the direction indicated by the arrow A and in the opposite direction (the direction indicated by the arrow B in FIG. 5). The operation block 32 is guided by the two rails 31a and 31b and moves linearly by a manual operation by an operator or driving of a motor or the like (not shown). When the operation block 32 is moved in the direction indicated by the arrow C, the rotary block 20 rotates in the direction indicated by the arrow A. Further, when the operation block 32 is operated in the direction opposite to the direction indicated by the arrow C in FIG. 1 (the direction indicated by the arrow D in FIG. 5), the rotating block 20 is opposite to the direction indicated by the arrow A (the arrow in FIG. 5). Rotate in the direction indicated by B). Two pins 34 a and 34 b are erected from the base 10, and these pins 34 a and 34 b are pins for contacting the operation block 32 and limiting the movement range of the operation block 32.

In the initial state before the optical fiber 2 (see FIG. 2) is inserted, the operation block 32 is moved in the direction of the arrow C, whereby the rotary block 20 is rotated to the limit in the direction indicated by the arrow A. .

In addition, on the base 10, the first side is disposed on both sides of the insertion direction (the direction indicated by the arrow I in FIG. 2) through which the optical fiber 2 (see, for example, FIG. 2) is inserted with the rotation block 20 interposed therebetween. A clamp 40A and a second clamp 40B are provided. The first clamp 40 </ b> A has a base portion 41 fixed on the base 10 and a lid portion 42 that can be opened and closed with respect to the base portion 41. The optical fiber 2 is passed over the base 41 and the lid 42 is closed on the base 41 as indicated by an arrow J in FIG. It has a sandwiching structure.

The other second clamp 40B also has a base portion 43 and a lid portion 44, the optical fiber 2 is passed over the base portion 43, and the lid portion 44 is indicated by an arrow K shown in FIG. The optical fiber 2 is sandwiched between the base part 43 and the lid part 44 by being closed on the base part 43.

However, the base portion 41 of the first clamp 40A is directly fixed to the base 10, whereas the second clamp 40B is movable with respect to the base 10. That is, two rails 45a and 45b extending in the x direction (optical fiber insertion direction) are fixed on the base 10, and the support block 46 is movably supported by the rails 45a and 45b. The base portion 43 of the second clamp 40 </ b> B has a structure that extends from the support block 46 and moves integrally with the support block 46. Further, a wall 401 fixed to the base 10 is erected at a position away from the pedestal 43 on the left side in the drawing, and the clamp 40B is separated from the clamp 40A between the pedestal 43 and the wall 401. A tension spring 402 is provided that moves in the direction and applies tension to the optical fiber 2 (see FIG. 2). Further, a load cell 47 for measuring the tension applied to the inserted optical fiber 2 is installed here, but the load cell 47 may be omitted.

The support block 46 is linearly moved by being guided by the two rails 45a and 45b by a manual operation by an operator or driving of a motor or the like (not shown). Two pins 48 a and 48 b are erected from the base 10, and an arm 49 extends from the support block 46 between the two pins 48 a and 48 b. These two pins 48 a and 48 b and the arm 49 are for limiting the movement range of the support block 46.

Also provided here is a movable latch 403 that is rotatable in the direction indicated by the arrow M and in the opposite direction (the direction indicated by the arrow N in FIG. 6). When the base portion 43 of the second clamp 40B is moved in the direction indicated by the arrow E against the tensile force of the tension spring 402 and the movable latch 403 is rotated in the direction indicated by the arrow M, the arm 49 is moved to the movable latch 403. Once locked, the base 43 remains in the state of movement in the direction indicated by arrow E. The support block 46 and the base portion 43 and the lid portion 44 that move integrally with the support block 46 are moved in the direction of arrow E in the initial state, and the arm 49 is locked by the movable latch 403. As will be described later, after the optical fiber 2 (see FIG. 2) is inserted and the optical fiber 2 is sandwiched between the first and second clamps 40A and 40B, the movable latch 403 is rotated in the direction of the arrow N shown in FIG. When the movable latch 403 is removed from the arm 49, the base 43 is pulled in the direction of arrow F shown in FIG. 6 by the tensile force of the tension spring 402, and tension is applied to the optical fiber 2. At this time, the tension force by the tension spring 402 is adjusted so that a predetermined tension described later is applied to the optical fiber 2.

Further, a cutting unit 50 for cutting the optical fiber is mounted on the base 10. The cutting section 50 is inserted through two rails 51a and 51b extending in the y direction, a blade holder 52 supported movably by the two rails 51a and 51b, and supported by the blade holder 52. And a blade 53 protruding in the y direction toward the optical fiber 2 (see, for example, FIG. 2). The blade holder 52 is linearly moved by being guided by the two rails 51a and 51b by a hand operation by an operator or driving of a motor or the like. Two pins 54 a and 54 b are erected from the base 10, and an arm 55 projects from the blade holder 52 between the two pins 54 a and 54 b. These two pins 54 a and 54 b and the arm 55 are for limiting the movement range of the blade holder 52. The blade holder 52 is moved in the direction of arrow G in the initial state so as not to prevent insertion of the optical fiber 2 (for example, see FIG. 2).

Here, it returns to the description of the rotation block 20 again.

As described above, the rotating block 20 is formed with the first anvil 20A and the second anvil 20B. The optical fiber 2 is inserted between the first and second anvils 20A and 20B as shown in FIG. 2, but the portions of the optical fibers 2 of the first and second anvils 20A and 20B are inserted. Are separated from each other by a distance d1 in the insertion direction. In the state where the rotating block 20 is rotated to the limit in the first direction indicated by the arrow A (the state shown in FIG. 1), the direction intersecting the insertion direction, that is, the pushing direction for pushing the inserted optical fiber 2 from the side. (Pushing the optical fiber 2 will be described later) is also in a state of being separated by a distance d2. The rotating block 20 is rotated in the direction of arrow B shown in FIG. By this rotation, the distance between the first and second anvils 20A and 20B is different from the distance d1 shown in FIG. 1 before insertion.

After the optical fiber 2 (see FIG. 2) is inserted, when the operation block 32 of the rotation operation unit 30 is moved in the direction indicated by the arrow D in FIG. 5, the rotation block 20 reaches the limit in the direction indicated by the arrow B in FIG. Rotate. The rotation limit of the rotation block 20 is adjusted so that bending stress within a predetermined range described later acts on the optical fiber 2 in a state where the rotation block 20 is rotated to the limit in the direction indicated by the arrow B.

Next, an operation procedure for cutting an optical fiber using the optical fiber cutting tool 1 will be described.

FIGS. 2 to 7 are diagrams showing each procedure of cutting an optical fiber and the movement of each part of the optical fiber cutting tool 1 associated therewith.

First, after confirming that each part of the optical fiber cutting tool 1 is in the initial state shown in FIG. 1, the optical fiber 2 is inserted in the direction of arrow I as shown in FIG.

The optical fiber 2 passes through a predetermined position on the base portion 41 of the first clamp 40A, passes between the first and second anvils 20A and 20B, and further, a predetermined position on the base portion 43 of the second clamp 40B. It is inserted to pass through.

Next, as shown in FIG. 3, the lid portion 42 of the first clamp 40 </ b> A that has been open until then is closed on the base portion 41 as indicated by an arrow J, and the base portion 41 and the lid portion 42 are closed. And hold the optical fiber.

Next, as in the case of the first clamp 40A, as shown in FIG. 4, the lid portion 44 of the second clamp 40B that has been open until then is placed on the base portion 43 as shown by the arrow K. The optical fiber 2 is sandwiched between the base portion 43 and the lid portion 44.

Further, the operation block 32 of the rotation operation unit 30 is moved in the direction indicated by the arrow D as shown in FIG. Then, the first anvil 20A is pushed by the arm 33, and the rotating block rotates in the direction indicated by the arrow B. When the first anvil 20A abuts on the pin 12, the rotation is positioned. By this rotation, the first and second anvils 20A and 20B advance toward the optical fiber 2 in the pushing direction (direction intersecting with the optical fiber insertion direction) and in opposite directions to each other. As shown in FIG. 5, it is pushed and bent into an S shape. The first and second anvil 20A, the insertion direction between 20B distance at this time becomes a distance corresponding to the distance L shown in FIG. 8 to be described later, the distance of the push direction a distance L ₂ shown in FIG. 8 The corresponding distance.

By the interval in the insertion direction of the first and second anvils 20A, 20B and the pushing amount of the optical fiber 2 by the first and second anvils 20A, 20B when the first anvil 20A contacts the pin 12 The S-shape of the optical fiber 2 is uniquely determined, and a certain bending stress acts on the optical fiber 2.

After the rotating block 20 is rotated in the direction indicated by the arrow B as shown in FIG. 5, the movable latch 403 is removed from the arm 49 as shown in FIG. Then, the support block 46 of the second clamp 40 </ b> B is pulled in the direction of arrow F by the tension spring 402, thereby applying a tensile stress to the optical fiber 2. The magnitude of the tensile stress is defined by the tension that pulls the optical fiber 2, and this tension is determined by adjusting the tensile force of the tension spring 402. If the load cell 47 is provided, the load cell 47 can also be used for confirmation.

In the state where the specified bending stress and tensile stress are applied to the optical fiber 2 as described above, the blade holder 52 of the cutting portion 50 is then moved in the direction indicated by the arrow H as shown in FIG. Then, the tip of the blade 53 comes into contact with the portion of the optical fiber 2 that is sandwiched between the first and second anvils 20A and 20B and pushed and bent into an S-shape, and the optical fiber 2 is tilted to a specified inclination (here, The optical fiber 2 is cut so as to form a cut surface having an inclination of 8 ° with respect to a plane perpendicular to the axial direction of the optical fiber 2.

FIG. 8 is a schematic diagram of a portion of an optical fiber sandwiched between two anvils.

Here, the tensile stress and bending stress acting on the optical fiber will be described with reference to FIG.

Table 1 shows the variables used here.

At this time, the tensile stress σ _t and the bending stress σ _b are respectively

It is represented by

The physical properties and shape of optical fibers are known in advance. Therefore, the bending stress σ _b is determined by the shape of the first and second anvils 20A and 20B, the restriction position of the rotation in the direction of the arrow B, and the position where the blade is brought into contact with the optical fiber. The tensile stress is also determined by the radius and tension of the optical fiber.

As described above, according to the optical fiber cutting tool 1 shown in FIG. 1, the tensile stress σ _t and the bending stress σ _b of the cut portion of the optical fiber 2 can be adjusted to appropriate values.

FIG. 9 is a diagram showing the optimum ranges of tensile stress and bending stress.

The horizontal axis represents tensile stress σ _t (GPa), and the vertical axis represents bending stress σ _b (GPa).

The range indicated by double circles in FIG. 9 is a favorable range in which the defects on the cut surface are 20 μm or less. A good range is that the combination of tensile stress σ _t and bending stress σ _b is (σ _t , σ _b ) = (0.08 GPa, 0.5 GPa), (0.2 GPa, 0.5 GPa), (0.2 GPa, It is a region surrounded by points of (0.6 GPa), (0.16 GPa, 0.9 GPa), (0.12 GPa, 1.3 GPa), and (0.08 GPa, 1.4 GPa). Specific values of L, L1, L2 and T falling within this range are, for example, L = 1.2 mm
L1 = 0.48mm
L2 = 0.007 to 0.243mm
T = 1 to 2.5N
It is. On the other hand, “× 1” is a range where cutting is impossible, “× 2” is a range where roll-off defects are generated, and “× 3” is a range where hackles are generated where irregularities are generated on the cut surface.

By configuring the optical fiber cutting tool 1 so that the tensile stress σ _t and the bending stress σ _b are in the range indicated by the double circle in FIG. 9, a high-quality, high-accuracy cut surface can be formed. .

In the above-described embodiment, the first and second anvils are integrated with the rotating block. However, these anvils are a pair of independent anvils that can move in the pushing direction intersecting the optical fiber insertion direction. It may be. Further, tension applying means such as a compression spring may be used instead of the tension spring.

DESCRIPTION OF SYMBOLS 1 Optical fiber cutting tool 2 Optical fiber 10 Base 11, 12, 13, 34a, 34b, 48a, 48b, 54a, 54b Pin 20, 21 Rotating block 20A, 20B Anvil 21 Connection part 21a Hole 22 Opening 23, 33, 49 Arm 24 Tension spring 30 Rotation operation part 31a, 31b, 45a, 45b, 51a, 51b Rail 32 Operation block 40A, 40B Clamp 41, 43 Base part 42, 44 Lid part 47 Load cell 50 Cutting part 52 Blade holder 53 Blade 401 Wall 402 Tension spring 403 Movable latch

Claims (3)

The optical fibers are separated from each other in the insertion direction in which the optical fiber is inserted, and are also separated from each other in the pushing direction intersecting the insertion direction, and the optical fibers inserted during the separation are advanced in the pushing direction and opposite to each other. A pair of anvils that are pushed and bent with,
The optical fiber inserted between the pair of anvils grips the portions before and after the insertion between the pair of anvils, respectively, and one moves relatively away from the other to apply tension to the optical fiber. A pair of clamps;
A blade that cuts the optical fiber by being pressed against the portion of the optical fiber that is pushed and bent by the pair of anvils and is held and pulled by the pair of clamps and sandwiched between the pair of anvils; An optical fiber cutting tool comprising: With a base,
The pair of anvils are integrally installed on the base as a rotation block limited to rotation within a predetermined rotation angle,
The pair of clamps are installed on both sides of the insertion direction on the base, with the rotating block in between.
The pair of anvils are separated from each other in the insertion direction, and the optical fiber inserted between the pair of anvils is also spaced apart from each other in the push direction in a state where the rotating block is rotated in the first direction. 2. The optical fiber cutting tool according to claim 1, wherein the rotating block is pushed and bent in the pushing direction and opposite to each other by rotation in a direction opposite to the first direction. The tensile stress σ _t and bending stress σ _b of the optical fiber, respectively,

However,
σ _t : tensile stress σ _b : bending stress L: distance in the insertion direction between the pair of anvils L1: distance in the insertion direction from the first anvil of the pair of anvils to the blade L2: the pair T: the optical fiber tension E: the Young's modulus of the optical fiber I: the second-order moment of the optical fiber r _f : the tensile stress σ expressed by the radius of the optical fiber The combination of _t and bending stress σ _b is
(Σ _t , σ _b ) = (0.08 GPa, 0.5 GPa), (0.2 GPa, 0.5 GPa), (0.2 GPa, 0.6 GPa), (0.16 GPa, 0.9 GPa), (0 .12 GPa, 1.3 GPa), and (0.08 GPa, 1.4 GPa), the distances L, L1, and L2 are set so as to be within the region surrounded by the points. The optical fiber cutting tool according to claim 1, wherein the tension T is applied.

Images